4.1 Species richness and abundance of pollinators in different habitats
Habitat types influence the species richness and abundance of insect pollinators. They are the highest in the open trail of the forest. In our study, species richness and abundance seem to have a direct relation to flower abundance. The abundance of flowers plays an important role in all flower visitors (Sjödin et al., 2008). The open trail of forest harbor, a comparatively thick layer of herbs and shrubs with varieties of wildflowers that suffice pollinators with nectar and pollen source. The quality and quantity of nectar and pollen matter a lot for the pollinators (Hicks et al., 2016). Trails of open forest were densely proliferated and covered by Ageratin aadenophora along with other wild herbs providing good resource plate form, especially for hoverflies and bees. Furthermore, weeds like Ranunculus repens andTrifolium repens were comparatively more abundant in the open trails. These flowers were preferred by bees and butterflies (Hicks et al., 2016; Chaguthi & Dyola, 2019). These plants can provide nectar and pollen to these insects (Erbar & Leins, 2013; Master & Emery, 2015). Adult, hoverflies require high energy for hovering flight that could be obtained from the local landscape with abundant flowers (Haslett, 1989; Meyer et al., 2009; Proesmans et al., 2019). In contrast, scanty flower resources also account for the decline in pollinator species richness and abundance in forest trails with canopy. Canopy cover increases shade in the understory herb and shrub of the forest lowering flower blooms and limiting pollinator’s movement (Proesmans et al., 2019). Sampled areas of the managed habitat in SNNP were open and inhabited by humans and disturbed by some human activities. Some previous study also shows that diversity of butterfly is negatively influenced by this factor of human disturbances (Kambach et al., 2013).